I agree, most new projects just coming into the blockchain space, don't know of bitcointalk I bet. They come straight from finance & developer backgrounds and BTCTalk isn't talked about by those in social media, just known to the OGs. I am sure a good percentage of them would come create a post if it clicked or they knew about it at the time.
If you don't know about Bitcointalk, why are you now in the Bitcointalk forum, this is the official forum for every cryptocurrency, so if there is a new project with a cryptocurrency background I don't think it would be wrong if the project developer wanted to create ANN in this forum, because ANN It can also be used as an additional promotion for people here, because in the Bitcointalk forum there are also very many active people.